On high feast days, the entire blue-glass front of this modern church opens up to reveal the small wooden church inside.

This airport currywurst stand is made out of retro airplane parts.

One man's personal kunstkammer, museum and shop.

Collection dedicated to funeral rites, equipment, and mourning rituals of the Viennese.

Museum devoted to the artificial language of Esperanto.

An exquisite Baroque church in Vienna's old town.

The resting place for anonymous victims of the Danube's dark waters.

The Natural History Museum that time forgot.

Tucked away in the Leiden city hall are a group of works by famed artist MC Escher.

Once the world's biggest telescope, it was later used as a coat hanger by a famous Dutch astronomer.

This public library and its impressive collection of academic books have not changed since the 17th century.

A trio of red, white, and blue stones embedded in the streets of Leiden are markers of medieval territory and law.

One of the last doorless, continuously moving elevators still in use in the U.K.

Long-secret natural history museum, featuring the skull of a "Terror Bird."

The names Lúthien and Beren can be found inscribed on the shared grave of the famous writer and his beloved wife and muse.

More than 450 years ago, an Italian nun became the first woman to paint the iconic subject.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

The middle finger of modernity.

The oldest operating pharmacy in the world features 800-year-old recipes.

A local student's chance encounter with Keith Haring led to the creation of one of Europe's largest murals.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

A pair of stones embedded in an Edinburgh street memorialize one of the city's last public hangings.

One of Edinburgh's oldest pubs hides a 19th-century skittles alley in the back.

Every birth, death, and marriage is recorded in these color-coded leather-bound books.